All recreation centers operated by Denver Parks and Recreation are open to the public on Friday to serve as cooling stations as temperatures approach triple digits.

All Denver Public Library locations except Central Library, Ross-Cherry Creek Branch Library and Blair-Caldwell African American Research Library are available to the public to serve as an indoor reprieve from the heat.

Temperatures in Denver are expected to reach 99 degrees on Friday, and the National Weather Service issued a heat advisory because of the conditions.  

Extreme heat can cause illness and occurs when your body is unable to dissipate heat effectively, according to the U.S. Centers for Disease Control and Prevention.

Denver Public Health & Environment offered these tips to avoid heat-related illness:

• Stay inside in an air-conditioned building as much as possible. Air conditioning is the No. 1 way to protect yourself against heat-related illness. If your home is not air-conditioned, visit one of Denver’s cooling stations.
• Drink more water than usual and don’t wait until you’re thirsty to drink water.
• Fans will not prevent heat-related illness in extreme heat. Take cool showers or baths to cool down.
• Don’t use the stove to cook. 
• Don’t drink alcohol or beverages that contain caffeine.
• Limit your outdoor activity, especially during the middle of the day when the sun is hottest.

Those who must be outside should follow these steps:

• Wear and frequently reapply sunscreen.
• Pace your activity and rest often.
• Pay attention if your muscles begin to cramp, which may be an early sign of heat-related illness. To combat cramping and heat-related illness, drink more water than usual.
• Wear loose, lightweight, light-colored clothing and a hat.